What an interesting and unique teaser! I got most of them after reading the hint--that helped a lot.
But I didn't get #10 because I thought there had to be less than three, although the hint didn't say that. Thanks--it was fun!

LOVED it, as stated above, fairly easy. Got most of them just looking at them, a couple took a bit of thought, but for some reason orthodox stumped me, could not for the life of me come up with it. Was obvious once I saw the answer.

Before the hint, I couldn't get any b/c I was trying to put in only one 'o', since there was no plural in the directions! After the hint I got eight of them easily; I missed onlooker and cockatoo! Fun!